Anduril Industries unveiled Steelfin, a family of surface-to-air interceptor missiles, on Oct. 12 at the Association of the U.S. Army’s annual meeting in Washington. The company says Steelfin is designed to shoot down cruise, ballistic and hypersonic missiles at a fraction of the cost of current interceptors, with flight tests slated to begin next year. Anduril did not give a unit price, name a customer, or say which U.S. service is backing the program, but said it plans to build several thousand Steelfin missiles a year in the short term.
Steelfin uses a two-stage architecture. The first stage is a solid rocket booster that can be swapped for different motors depending on range, speed, and packing requirements. The second stage is a common “terminal interceptor” that carries the airframe, electronics, software, and flight controls shared across the family, with open interfaces for different seekers and mission systems. Anduril says this allows it to build versions for every layer of air and missile defense, from short-range point defense to upper-tier ballistic missile defense, while aiming for a fraction of the cost of current interceptors in each class. The company did not specify benchmark costs, but a single Patriot PAC-3 MSE interceptor costs about $4 million, and the Missile Defense Agency is pursuing a separate low-cost interceptor effort with a target price below $750,000 per round.
Because variants share parts, Anduril says they can run down the same production line with the same tooling and workers, letting it shift output to whichever version is in demand. The company also says the common interfaces let it buy commercial components and use multiple suppliers.
Steelfin is designed to fire from launchers the U.S. military already fields, including the M903A2 launcher used by the Patriot air defense system, the U.S. Navy’s Mk 41 Vertical Launch System, the U.S. Army’s Typhon mid-range missile launcher, and newer containerized launchers. Anduril says it will work with existing fire control systems such as the U.S. Navy’s Aegis and the U.S. Army’s Integrated Battle Command System (IBCS), rather than requiring a new command network.
The company has completed ballistic testing with representative air vehicles but has not yet flown a Steelfin missile. Anduril says it has been developing Steelfin for years while investing alongside multiple customers. The launch comes as U.S. air defense stocks have been drawn down by combat in the Middle East. This month alone, Raytheon received contracts worth up to $6.3 billion for SM-3 Block IB interceptors and up to $24.4 billion for SM-6 missiles to replenish U.S. Navy inventories. Anduril already makes smaller counter-drone interceptors such as Roadrunner and Anvil, but Steelfin is its first family aimed at cruise and ballistic missiles.
In a related development at AUSA 2026, Northrop Grumman revealed it had invested $100 million in its Raid Hunter gun-based air defense capability, which the company claims could reduce the cost of individual engagements by 95.5% compared with interceptor missiles.
Sources: Defence Blog · Shephard Media